ProductionModePlugin.js

var async = require("async");
var Extractor = require("./Extractor");
var fs = require("fs");
var mkdirp = require("mkdirp");
var path = require("path");
var stringify = require("json-stable-stringify");

function alwaysArray(stringOrArray) {
  return Array.isArray(stringOrArray) ? stringOrArray : stringOrArray ? [stringOrArray] : [];
}

function arrayClone(array) {
  return array.slice(0);
}

function compareJson(a, b) {
  return JSON.stringify(a) === JSON.stringify(b);
}

function jsonKeyValue(key, value) {
  var json = {};
  json[key] = value;
  return json;
}

// Returns new deeply merged JSON.
//
// Eg.
// merge( { a: { b: 1, c: 2 } }, { a: { b: 3, d: 4 } } )
// -> { a: { b: 3, c: 2, d: 4 } }
//
// @arguments JSON's
function merge() {
  var destination = {},
    sources = [].slice.call(arguments, 0);
  sources.forEach(function(source) {
    var prop;
    for (prop in source) {
      if (prop in destination && typeof destination[prop] === "object" && !Array.isArray(destination[prop])) {
        // Merge Objects
        destination[prop] = merge(destination[prop], source[prop]);
      } else {
        // Set new values
        destination[prop] = source[prop];
      }
    }
  });
  return destination;
}

function writeMessagesFile(filepath, data) {
  process.nextTick(function () {
    async.series([
      function(callback) {
        mkdirp(path.dirname(filepath), callback);
      },
      function(callback) {
        fs.writeFile(filepath, stringify(data, { space: 2 }), callback);
      }
    ]);
  });
}

function ProductionModePlugin(attributes) {
  this.attributes = attributes;
}

ProductionModePlugin.prototype.apply = function(compiler) {
  var attributes = this.attributes;
  var developmentLocale = attributes.developmentLocale;
  var extractor = new Extractor();
  var messages = attributes.messages;
  var writeMessages = attributes.writeMessages;

  // Map each AST and its request filepath.
  compiler.parser.plugin("program", function(ast) {
    extractor.asts[this.state.current.request] = ast;
  });

  // Sneaks in modules that `require("react-globalize")` and create custom
  // precompiled formatters/parsers for them.
  compiler.parser.plugin("call require:commonjs:item", function(expr, param) {
    var request = this.state.current.request;
    if(param.isString() && param.string === "react-globalize") {
      extractor.getDefaultMessages(request);
      extractor.getExtracts(request);
    }
  });

  compiler.plugin("globalize-before-compile-extracts", function(locale, attributes, request) {
    var originalMessages;
    var defaultMessages = extractor.getDefaultMessages(request);
    var extracts = extractor.getExtracts(request);

    if (extracts) {
      attributes.extracts = attributes.extracts ? arrayClone(alwaysArray(attributes.extracts)) : [];
      [].push.apply(attributes.extracts, alwaysArray(extracts));
    }

    // Note react-globalize-compiler actually extracts the default messages for
    // Globalize and react-globalize <FormatMessage>s. Therefore, the fact
    // defaultMessages is true means there are messages set either by Globalize
    // methods or <FormatMessage>.
    //
    // If in the future, Globalize supports default messages, probably
    // globalize-compile will handle the Globalize default messages and
    // react-globalize-compiler will handle the react-globalize default
    // messages. Therefore, this code will need changes.
    if (defaultMessages) {
      originalMessages = attributes.messages;

      if (locale === developmentLocale) {
        // Overwrite it with the extracted default messages.
        attributes.messages = jsonKeyValue(locale, defaultMessages);
      } else {
        // Populate the missing messages with the default messages.
        attributes.messages = merge(
          jsonKeyValue(locale, defaultMessages),
          attributes.messages || {}
        );
      }

      // Write messages if:
      // 1: `writeMessages` is true, and
      // 2: processing the whole chunk (i.e., the final i18n bundle where
      //    `request` is null), and
      // 3: messages have changed
      if (writeMessages /*1 */ && !request /* 2 */ && !compareJson(originalMessages, attributes.messages) /* 3 */) {
        var filepath = messages.replace("[locale]", locale);
        writeMessagesFile(filepath, attributes.messages);
        if (locale === developmentLocale) {
          console.log("Generated `" + filepath + "` using the default translation.");
        } else {
          console.log("Populated the new fields of `" + filepath + "` using the default translation.");
        }
      }
    }
  });
};

module.exports = ProductionModePlugin;